Due to the energy crises presently existing, the attention of engineers and inventors has been directed to solar collector-heat exchangers which are designed primarily for the heating of homes and other premises. The heat exchanger unit, that is the apparatus that actually transfers heat, is the very heart of such a solar collector-heat exchanger. If the apparatus is to be mounted on the roof of a house or other building, and particularly a home, there are space limitations which must be accommodated. Thus, if the installation is bulky and occupies too much space on the roof, it will not be acceptable to the public for either one or both of two reasons. In the first place, if it is unusually massive and has great weight it is not susceptible of installation on a presently existing building because of the necessity of the building structure supporting the weight of the exchanger; and secondly, the apparatus which is installed on a roof should be of a compact thickness and occupy a small area to avoid an unsightly appearance.
Every solar collector-heat exchanger, for its very nature, must include a surface onto which the sun's rays are directed and collected. The heat so generated must be transferred to the underside of this surface. Thus, efficiency in the transfer of heat is of the utmost importance in a solar collector-heat exchanger.
In the patent application above identified, the heat exchanger unit has many characteristics of the subject heat exchanger. Thus, it includes longitudinal channels provided by an intermediate flat sheet and corrugated sheets on either side thereof. Air is caused to flow through these channels and is either heated or cooled by the temperature which occurs on the upper side of the exchanger. A blower is provided to force air through these channels. It is deemed desirable to provide a heat exchanger which will function to achieve both heating and cooling effects without the use of a blower.
The prior art is singularly lacking in a solar collector heat exchanger which is adapted not only to heat houses and other premises by solar heat, but which is also capable of either heating or cooling these premises by passing a film of liquid of a required temperature thereover. Now known heat exchangers of the type with which this invention is concerned are also not adapted for installation in the vertical walls of a building.